Add an API for teams (#1562)

* Add Team resource to API

* Add team memer endpoints

* Add team invites endpoint

* Add token endpoints

src/tests/api/conftest.py

@@ -71,6 +71,8 @@ def event3(organizer, meta_prop):
 def team(organizer):
     return Team.objects.create(
         organizer=organizer,
+        name="Test-Team",
+        can_change_teams=True,
         can_manage_gift_cards=True,
         can_change_items=True,
         can_create_events=True,